Various proposals have been made for a walking assistance device that is adapted to mount an actuator to the hip joint or knee joint of a person having a walking impediment due to injury, disease or weakened muscle resulting from aging, so that the power from the actuator can be used to assist the movement of the lower limb.
Conventionally, in such a walking assistance device, it was necessary to fasten corset-like support members onto the hip, thigh and lower leg portions to securely mount rotational actuators on a side of the hip joint and knee joint and transmit the drive torque from the rotational actuators to the lower limb.
However, the prior art devices, such as those disclosed in Japanese Patent Application Laid-Open Publication No. 58-163364 (FIGS. 1-4), are designed mainly for the purpose of securely mounting the actuators to the body, and tend to hamper free movements of the body. Further, because it is impossible to three-dimensionally coincide the position of joints of the human body and the support member, as shown in FIG. 6, for example, an offset existing between the center of the hip joint and the actuator mounted on a side of the hip joint causes a difference E in the motion between the human body and the support member when the leg is swung in a lateral direction. For this reason, in the example of FIG. 6, it is quite difficult to mount a knee joint actuator to the leg so as to be capable of following the lateral movement of the thigh around the hip joint.